Quarterly report pursuant to Section 13 or 15(d)

Net Income (Loss) Per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Detail)

v2.4.1.9
Net Income (Loss) Per Share - Computation of Basic and Diluted Net Income (Loss) Per Share (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Apr. 04, 2015
Mar. 29, 2014
Net (loss) income per share:    
Net (loss) income attributable to U.S. Auto Parts $ (60)us-gaap_NetIncomeLoss $ 201us-gaap_NetIncomeLoss
Dividends on Series A Convertible Preferred Stock 60us-gaap_PreferredStockDividendsIncomeStatementImpact 59us-gaap_PreferredStockDividendsIncomeStatementImpact
Net (loss) income available to common shares $ (120)us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic $ 142us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic
Denominator:    
Weighted-average common shares outstanding (basic) (in shares) 33,720us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted 33,384us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted
Common equivalent shares from common stock options and warrants (in shares) 0us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment 774us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment
Weighted-average common shares outstanding (diluted) (in shares) 33,720us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding 34,158us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding
Basic net income (loss) per share (in dollars per share) $ 0.00us-gaap_EarningsPerShareBasic $ 0.00us-gaap_EarningsPerShareBasic
Diluted net income (loss) per share (in dollars per share) $ 0.00us-gaap_EarningsPerShareDiluted $ 0.00us-gaap_EarningsPerShareDiluted